The invention relates generally to plastic containers, and more specifically to molded polymeric bottles or jars.
In providing a container for commercial packaging of food products, among the considerations that must be addressed are the ability of the container to receive product in filling operations; the degree of difficulty that will be encountered by the consumer in dispensing product from the container; the ability of the container to withstand various loads, such as stacking loads, during filling, sealing, shipping, display and consumer use; the ability of the container to be packed efficiently among like containers; and the appearance of the container.
Plastic bottles and jars are widely used for food products, and provide lightweight, relatively inexpensive packaging. One disadvantage of many plastic containers is that they are subject to panelling, i.e., localized inward deflections or dents which significantly distort portions of the container. Panelling occurs as a result of pressure in the sealed interior of the container dropping below atmospheric pressure. Such a pressure drop may be caused by cooling of the product after filling or by other factors. Panelling is undesirable not only due to the fact that it may reduce the container's ability to stably withstand compressive vertical loading when upright, but also due to its negative aesthetic impact, making the container appear damaged or deformed and therefore possibly unacceptable to the consumer.
A general object of the invention is the provision of a lightweight, economical plastic jar which is capable of responding to interior pressure reductions without panelling. Further objects and advantages of the invention are set forth below.